


A Stunning Performance

by spiritboards



Category: Undertale (Video Game)
Genre: 69 (Sex Position), Cunnilingus, DFAB reader, F/M, Non-binary Reader Insert, Other, Reader-Insert, Vaginal Fingering, gratuitous heart goop, heart touching
Language: English
Status: Completed
Published: 2015-11-05
Updated: 2015-11-05
Packaged: 2018-04-30 03:35:35
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,561
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5148779
Author URL: https://archiveofourown.org/users/spiritboards/pseuds/spiritboards
Summary: <blockquote class="userstuff">
      <p>The title sucks, I know. I might do a series of Undertale reader inserts because they're fun.</p>
    </blockquote>





	A Stunning Performance

**Author's Note:**

> The title sucks, I know. I might do a series of Undertale reader inserts because they're fun.

Mettaton’s circuits were always buzzing after a show, still riding the high he got from performing in front of others. After a show he felt like he could do absolutely anything and the only thing he wanted was to prolong that feeling. He made his way backstage, a smug grin planted on his face as he swung open the door to his dressing room.

  
“Hello, darling!” He closed the door shut behind him with one swift kick, making his way over to the couch where you had been sitting. “Did you catch any of that or were you waiting back here the entire time?”

“You know I wouldn’t miss any of your performance,” you told him. And it was true.“I’ve only been here for a few minutes." 

"Splendid, darling!” He held one of his gloved hands out to caress your cheek, his grin turning mischievous as he got an idea. “Then we’ve no time to lose!" 

Before you could ask what he meant, his lips were pressed against yours, the synthetic material slightly warm due to him over-exerting himself during the show. His silicone tongue made its way past your lips as your arms moved up around the back of his neck to steady yourself. He tasted like artificial cherries, only better. Mettaton’s other hand pressed against the back of your head, his fingers tangled in your hair as he pulled your face even closer, eliciting a slight moan from your lips. He pulled away much too soon for your liking, letting out a low chuckle.

"I almost forgot humans have to breathe! Sorry about that, darling.” Truth be told you had almost forgotten as well, only just realizing you had practically been gasping for air. 

Mettaton smirked, a mischievous look in his eye as he looked you up and down. Your face was flushed and you could feel moisture on your lips, still tingling from the kiss. Having all the attention on you all of a sudden felt quite awkward. Seeing you uncomfortable, he took one of your hands into both of his, planting a kiss on the top as if you were royalty. “No need to be self conscious, gorgeous. You look quite dazzling. Especially like this." 

His compliment couldn’t help but make you smile, despite your embarrassment. You managed to stutter out a "thank you” before you were silenced by another passionate kiss. 

This one was cut short much faster than the previous one as he moved from your lips down to your neck, planting little kisses as he went and grazing your skin softly with his sharp, metal teeth. His hands began to roam your body freely, one snaking its way up the back of your shirt and the other landing at your waist, his fingers moving under your waistband and teasing your bare skin pleasantly. 

“Mmm, Mettaton,” you moaned.He was now at your collar bone, still kissing down your body. He raised his eye to look at you seductively. “Hmm? Do you like that, darling?” He asked teasingly, moving the hand at your waist lower, rubbing against the fabric of your crotch and causing you to let out another moan.

You sat up on your knees in order to grind harder against his hand, your head leaning against Mettaton’s shoulder. The sensation felt so good, but you needed more. Your clothing had never felt so restricting before. You moved your own hands around his body now, stopping at the heart container around his waist. The plump, pink heart looked as if it was pulsating. You cautiously touched an index finger to it and Mettaton moaned slightly. The heart felt squishy and slightly porous. As you pressed your finger deeper, a gooey pink substance leaked from it. 

You were more curious than anything, but Mettaton seemed to be enjoying what you were doing, so you pressed your entire hand against his heart, squeezing gently.  
“Ooh, darling!” He gasped, his hips bucking against you suddenly. “Mm, harder!” You obeyed, squeezing his heart harder, causing even more of the pink goo to come out. He moaned, practically writhing against you before  pushing you down against the couch forcefully. Evidently he was just as eager as you were. 

He crawled forward on top of you, snatching your wrist and placing a goo covered finger into his mouth, sucking it clean. He let go, slipping his fingers under your waistband once more, tugging your clothes off. As he moved upwards to kiss you again, you wriggled them the rest of the way off of your legs and feet. 

You felt something cold rubbing against your slit. “So wet already, darling,” he moaned against your mouth. “And we’ve barely even started.” His middle finger teased your clit, rubbing around it in small circles. 

Mettaton pulled back from the kiss finally, reaching into his heart container to pull the heart out. “Take care of this for me, will you?” He handed it to you before sliding downward until his head was between your legs. His chilly hands were on the tops of your thighs, holding your legs apart. He looked up at you before planting kisses on your inner thigh, sucking a little before finally letting his tongue dart out to lap at your clit. With each movement of his tongue, you gripped his heart tighter, feeling his lips vibrate as he moaned against you. 

It was almost too much to bare. You held his heart up to your mouth in an attempt to stifle your moans, the pink goo falling onto your lips. You stuck your tongue out to taste it; the same cherry flavor as before, only now you needed more of it. 

“Mn, darling, I have …an  _idea_ ,” Mettaton sat up, grinning. As difficult as self control was at the moment, you waited patiently for him to explain. He gently took his heart back from you, placing it in its container again messily before fiddling with the dial on his chest plate. “Ah, that should do it,” he said to himself before giving you a reassuring wink. He pulled you up into his lap, giving you a quick peck on the nose before laying down on his back underneath you.“Now be a dear and turn around, will you?" 

You did as you were told, shifting around on top of him until your head was now between his legs. "Mmf!” You grunted as he unexpectedly pulled your legs down further toward his face until your thighs were on either side of his head again, causing you to be face to face with his heart. 

“Let’s continue where we left off then, hmm?” He didn’t waste any time, moving his face between your legs, licking and kissing and nibbling every square inch he could manage. 

You were immediately thrown back into ecstasy, trying not to move your hips too much. You moved your lips to his heart once more, lapping up all the goo that was still there. You held the heart in both hands, squeezing as you licked and kissed it, trying to mimic the motions Mettaton was doing between your own legs.

“Mmyes, darling, just like that!” You spread your legs as far apart as you could, feeling like you were made of jelly. He prodded at you with first one finger, and then two, slipping them inside you, moving slowly as if he were exploring. Your breathing was heavy and you were panting around the heart in your mouth. 

You heard a small click from behind you and practically saw stars as Mettaton’s tongue began to vibrate against your clit. You became a writhing mess on top of him, pleading with him to  _please just go faster I beg you_ , and he complied, picking up the pace with his fingers as your entire body seemed to melt into him. The grip on his heart tightened with every movement and you could feel him shudder against you.   
Static and beeps soon began to erupt from Mettaton’s speaker, but he didn’t stop. It startled you and you paused your motions momentarily, wanting to make sure he was alright.“Ooh, darling,” you could hear his voice, strained as it was around the static and beeping noises. “—no don’t stop! You’re… doing  _wonderfully_!" 

Taking that as a sign he was more than okay, you picked up the pace with your tongue on his heart once more, prodding it with your fingers every time your tongue grew tired, being as rough as you could allow yourself to be with something so seemingly delicate.

His fingers pumped away inside you as his tongue vibrated, and you couldn’t help grinding against his face. The room was filled with the sound of your moans, broken up by dial up noises and other mechanical sounds. You felt your body tense up one last time and you barely heard Mettaton among the noise and the fogginess of your own mind.

"Mm …. _sweetheart_ … I’m going to—!"Both of you collapsed at the same time, panting together as he turned the dial on his chest once more. His body was warmer than usual, warmer than it had been even after the show, and you were slightly worried he might overheat. 

"Well, darling,” he said, his voice now back to normal as he slid out from under you, sitting up. “I do believe that was our  _best_  performance yet!” 

 


End file.
